Electrochemical cells, such as fuel cells, generate electrical power through the electrochemical reaction of a reactant and an oxidant. An exemplary fuel cell has a membrane electrode assembly (MEA) with catalytic electrodes and a proton exchange membrane (PEM) sandwiched between the electrodes. In preferred PEM type fuel cells, hydrogen is supplied as a reductant to an anode and oxygen is supplied as an oxidant to a cathode. PEM fuel cells reduce oxygen at the cathodes and generate an energy supply for various applications, including vehicles.
For ease of production, fuel cells are typically manufactured using subassemblies. A fuel cell will contain as a subassembly either a catalyst coated membrane (CCM) or a catalyst coated diffusion media (CCDM). Various manufacturing methods have been developed for manufacturing CCMs. Lamination techniques used to manufacture CCDMs often result in the presence of a significant amount of stress that is visually indicated by a “bowing” effect in a laminated subassembly. Post-lamination relief of stress is often accompanied by unwanted cracking and destruction of the diffusion media.
Various means of circumventing this stress-relief problem have been explored and have included an undesired altering of physical characteristics of the fuel cell components, including size and shape. Thus there remains a need for a method of manufacturing CCDM at a high volume production that avoids problems associated with known processes and improves fuel cell performance, efficiency, and lifespan.